A Study on the Methylation of Notch1 Gene Promoter in CD4~+ T Cells Isolated from Asthmatic Rat Lung Tissue

Objective To examine the expression of promoter CpG island methylation of Notch1 gene and explore the variable sites for DNA methylation in lung CD4+T cells of asthmatic rat models.Methods An ovalbumin (OVA)sensitized-challenged asthmatic rat model was established.Total T cells were isolated and CD4+T lymphocytes were purified using magnetic beads.Twenty Wistar rats were randomly divided into a control group and an asthma group(n=10 in each group).CD4+T cells were isolated by immunomagnetic beads and identified by flow cytometry(FCM).Realtime PCR was employed to examine the mRNA expression of Notch1 gene in lung CD4+T cells and the methylation level of Notch1 gene was examined by methylation-specific PCR.Results The mRNA expression of Notch1 in lung CD4+T cells of the asthma group was 2.254±0.403 times as much as that of the control group.The total methylation level of asthma group was lower than that of the control group(0.150±0.108 vs.0.300±0.667,P0.01).Conclusion Promoter demethylation is one of the major mechanisms of Notch1 gene up-regulation in pathogenesis of asthma.